The Cactus alkaloids weberine, norweberine and their 1-methyl congeners are 5,6,7,8-tetramethoxy-substituted 1,2,3,4-tetrahy droisoquinolines. They were synthesized from 2,3,4,5-tetramethoxybenzaldehyde and the derived phenethylamine by Pictet-Spengler and Bischler-Napieralski synthesis. Totally synthetic weberfine was identical with the natural alkaloid isolated from the Mexican cactus Pachycereus weberi. Single crystal X-ray analysis of representative TIQ revealed that all four methyl groups attached to the aromatic oxygens are out-of the plane of the aromatic ring, a novel and interesting finding.